Air Needle Sander

The needle scaler did a great job of removing the heavy undercoating and revealing the solid, primer-coated sheet metal. The tool didn’t remove the primer.

Heavy undercoating treatments were popular in the ‘’70s and ‘80s. Now that such cars are becoming collectible, cars are showing up that have every piece of sheet metal looking like new. That’s nice, but the undercoating isn’t “factory original” and sometimes it collects moisture and dirt.

Before the car can be refinished, the “dirty work” of cleaning the underside, engine, engine bay, wheel wells and other such areas has to be carried out. Also, there is no way to get around removing the old undercoat. This kind of clean up is a lot harder than it sounds at first

If the car is to be completely taken apart, the undercoat can be removed through media blasting. There are also chemical undercoating removers, but they are messy. Scraping, scratching, wire brushing and “sandpapering” can also remove undercoat—if you’re lucky. It may peel off or it may stick like glue.

Another way to remove undercoat is with a needle scaler tool like the Klutch Composite Pistol-Type Air Needle Scaler that webought from the Northern Tool (www.northerntool.com) catalog. This tool is engineered to scale unwanted coatings off sheet metal. The needle scaler has a lightweight composite housing, 19 steel needles and a trigger control for top efficiency and productivity.

An anvil inside the tool slaps the tentacle like needles against the undercoating and the pounding, vibration and heat take the undercoat off.

Needle scalers remove unwanted materials from surfaces without damaging the metal below. They use vibrating metal “tentacles” (called needles) to shake products like undercoating loose and scrape off any unwanted debris.

The needle scaler tool works hard, creates friction and heat and needs a good amount of lubrication. Installing an automatic oiler on the inbound air line is the preferred way to handle this. The instruction booklet that comes with the tool shows how to do this. If you opt for manually oiling the tool, it must be lubricated religiously per the manufacturer’s instructions.

According to Dave LeVesseur of Northern Tool, the Klutch Needle Scaler must be lubricated daily. Doing this is very important, but the properly lubricated tool has a good reliability rating. Run the scaler along all metal surfaces until they all have been cleaned of nearly all undercoating. Eastwood’s spray-on Undergone undercoating remover (www.eastwood.com) will make the job easier.

Here is an example of the amount of debris that the needle scaler removed from just half of one wheel well of a car.

Two kinds of needle scaler tools are available. The pistol type is recommended for undercoating removal on automobiles. The pistol grip design provides more control. Barrel style tools are your other option. They work well, too, and may be able to get into some spots where the pistol shape won’t fit.

Needle scalers come in a wide range of prices from under $50 to over $500. With proper lubrication, tools in the $50 to $100 range should do the job of undercoating removal and last. On many models, the needles can be replaced when use of the tool wears down the edges and reduces their effectiveness.